Dissident Irish republican paramilitary groups have been supplying firearms to some of Britain's most violent gangs, fuelling the rise in gun crime, the BBC has learned.

There has been a trade in weapons originating from the Continuity IRA based around Limerick in the Irish Republic into cities such as Manchester and Birmingham, BBC Radio 4's File on 4 programme has found.

Sources within the National Criminal Intelligence Service have confirmed they are aware of incidents of paramilitary dissidents smuggling weapons into the UK.

Irish justice minister Willie O'Dea, who represents Limerick in the Irish parliament, told the programme he understands large family groups with connections in both cities have been acting as intermediaries for the trade in illegal weapons.

Mr O'Dea said: "Some of the people who are involved in crime in the Limerick area have also got a base in the UK, in and around Manchester and various cities in the centre of the UK.

"The reports I've heard and what I've seen would indicate that those people are travelling between Ireland and the UK and are involved in various types of smuggling which involve both jurisdictions, of smuggling drugs and smuggling guns."

Weapons sales

In one operation firearms were swapped with one of Britain's biggest street gangs in exchange for drugs.

The weapons were transported in furniture vans driven between the two countries, according to a former Home Office-funded researcher who works with street gangs in Manchester.

The gang has been branching out into other British cities, selling drugs and moving weapons around the country.

But Greater Manchester Police said there was no firm evidence of guns being supplied from the Irish Republic.

In Birmingham, weapons have been offered for sale from car boots of vehicles cruising parts of the city which have had shootings, according to community workers trying to stop gang violence.

Earlier this year two young women, Charlene Ellis and Letisha Shakespeare were killed after being caught up in what was believed to be a feud between two of the city's rival gangs.

The latest Home Office figures show gun crime rose by 35% last year, with the home secretary telling the recent Labour party conference it was time to tackle gun runners bringing weapons into the UK.

File on 4's reporter Allan Urry told BBC Radio 4's Today programme that it was difficult to estimate how many weapons were being smuggled into the UK.

"We are not able to say if this is a major supply route, but it is clear that there is a lot of shootings around British cities and it is clear from information we've had from both Manchester and Birmingham that guns are getting through from across the water."